2001 130 2 stroke compression range

[bigdummy]

Looking at a 2001 130 2 stroke that has been sitting for quite a while.
Local dealer got it on a trade in last spring and they want it gone, they are giving me access to test (at their yard) to make sure it runs .
Taking a remote tank with pre-mix and a good battery with me.

Can someone provide what the compression readings should be (I realize the accuracy from sitting is suspect). I've been told some Yamaha's were designed with different compression ratios at different sets of cylinders. Just trying to find out if this engine has that in case my numbers are dramatically different.

Thanks in advance

[boscoe99]

Cylinders 3 and 4 have a slightly lower compression ratio (6.5) than do cylinders 1 and 2 (6.8).

I would expect that you will see approximately 125 psi or so on your compression gauge. Throttle wide open, engine hot from the motor having recently been run, battery fully charged, crank the motor until the pressure stops rising.

[bigdummy]

Thank You. Good information, I wonder how many motors have gotten poor reports because of pressure differentials that are actually designed into the motor?

[rodbolt17]

10 psi bank to bank and you are golden.
you will find hot or cold throttle open or closed the results will stay about the same.
it is a two stroke smoker.

[bigdummy]

A little more help please.
Motor starts and runs on portable tank-didn't perform compression check yet (wasn't feasible at time). I can smell old/bad gas and assume carbs and fuel system will need cleaning.


I'm trying to determine "what" this motor is.

This is what information I can read from data plate

Top line - 130 T (and what looks like the bottom half of an "X") and the remaining numbers missing
Second Line- 6Li X 707890
Lower right corner - S

Tag on other side of motor has been painted over

Trying to get a good ID on motor so I can order correct manual and parts.

I want to Thank everyone again for their help and sharing of knowledge.

[boscoe99]

PID is 6L1X 707890. Model is a 130TXRZ.

https://www.boats.net/catalog/yamaha...r/2001/130txrz

https://www.boats.net/search?q=LIT-18626-04-16

https://www.boats.net/search?q=LIT-18616-02-03

[bigdummy]

Thank You for the rapid response!
I'm guessing the last link would be the service manual that will provide the information for adjustments, service, etc?

[walleye1]

Boscoe is the best.